2021/05/25 by Amata, Luca, Ficarra, Antonino, Crupi, Marilena · 1 citation
#05E40 #13B25 #13D02 #16W50 #68W30 #Commutative Algebra (math.AC) #FOS: Mathematics
paper · doi:10.48550/arxiv.2105.11944
Let K be a field and let S=K[x1,…,xn] be a standard polynomial ring over a field K. We characterize the extremal Betti numbers, values as well positions, of a t-spread strongly stable ideal of S. Our approach is constructive. Indeed, given some positive integers a1,…,ar and some pairs of positive integers (k1,ℓ1),…,(kr,ℓr), we are able to determine under which conditions there exist a t-spread strongly stable ideal I of S with βki, kiℓi(I)=ai, i=1, …, r, as extremal Betti numbers, and then to construct it.